Unit One: Velocity
1. To get to the forrest, we had to drive about an hour. The road was windy, and the speed limit changed often. These two things meant that we were never traveling with constant velocity or acceleration, because both our direction and speed were changing almost constantly.
Unit Two: Newton's Second Law
2. Newton's second law states that acceleration is directly proportional to force and inversely proportional to mass. This was evident this weekend when we were skipping rocks in the stream by our campsite. The harder we threw the rocks, the faster they went, while lightly tossing rocks did not make them go as far. Similarly, we could see this in the size of the rock. The lighter rocks went faster than the heaver rocks.
Unit Three: Newton's Third Law
3. We saw Newton's Third Law when we were hiking. The 3rd law states that every action has an equal and opposite reaction. When hiking up a step hill, just as we push the ground backwards, the ground pushes us forward. However, we pushed the ground harder that the ground pushed us; this was the reason that we were able to climb the hill.
4. Although our camping trip only involved hiking, some camping trips require rock climbing. For rock climbing, nylon ropes are used instead of cotton or wool ropes. This is because when a climber is falling, they will go from start to stop, no matter the surface they are landing on. This change in momentum (p=mv) is represented by the equation ∆ p= p final - p initial, and is the same no matter the surface they are landing on. Since the ∆ p is constant, and we know that ∆ p=J, we know J is also constant. Since J is the same, the rope will increase the amount of time taken to stop as a result of the bounce. An increase in time means a decrease in force. More time=less force=safe landing.
Unit Four: Rotation
5. Camping requires a lot of materials, and if you're backpacking, that can mean carrying a heavy pack. If you're not balanced, a heavy pack can cause you to fall over-- what a disaster! This disaster may occur as a result of torque (force x lever arm). If your body's center of gravity is too high or off center, there could be a torque, causing you to fall. For this reason, backpackers must widen their stance, thus widening their base of support. This allows for the center of gravity to be over the base, greatly decreasing the likelihood of falling over because of a heavy backpack.
Unit Five: Work and Energy
6. Closely related to hiking and camping in a literal sense, work and power are also related with Physics! We can see machines, a tool that reduces the FORCE of an object (not its energy or work) in bear hangs, used to get food and toiletries out of a bear's reach. At well established campsites, often park rangers will construct bear hangs with pulley systems, like shown below. Pulleys are a form of machine that reverse the direction of the force you are applying. This greatly decreases the amount of force, making the work (work= force x distance) easier.
Unit Six: Charges and Electricity
7. Perhaps one of the most obvious needs while camping is a flashlight or headlamp. It was great learning about how batteries and lightbulbs worked, so that I could transfer that knowledge to my fellow campers. Batteries use DC or direct current, meaning that the current flows in one direction from the high energy end to the low energy end. When connected with a current carrying wire to a lightbulb, the circuit causes current to run thru the bulb, lighting the flashlight. Who knew Physics made it possible to see at night out in the woods?!
8. A not so fun part of camping is the threat of rain, specifically thunderstorms. Lightening occurs when clouds in the sky rub together, and become charged thru friction. This causes the top of the cloud to become slightly positive and the bottom to become slightly negative. The ground then becomes slightly positive thru induction from the negative part of the clouds. Since opposite charges attract, the positive charges in the ground start to creep up towards the negative charges in the clouds. If the path is completed, energy is released in the form of sound (thunder), heat, and light.
Unit Seven: Magnetism
9. After a great weekend camping, we had to return to campus. This required a second hour-long drive in the car, which is also powered by Physics! Motors in cars, although more complex, rely on the same basic principles to work as the simple motors we worked on in class. Motors require only two things: a magnet and a current carrying wire. To work, motors rely on the torque felt by the current carrying wire's moving charges. This force causes a torque, which spins the motor. Motors convert electrical energy to mechanical energy, and are necessary to working cars.
10. On the drive home, campers will undoubtedly pass a stoplight. The sensors that tell the traffic light when a car is waiting also has Physics to thank. In this case, electromagnetic induction is our hero! Under the road, there are coils of current carrying wire. When a car, essentially a giant magnet, passes over the wire, it changes the magnetic field of the wire. This change in magnetic field induces a voltage, which causes a current, which acts as a signal to the traffic light. Without electromagnetic induction, the smelly campers would be waiting forever!
So that is the The Top Ten Applications of Physics While Camping. Although the bug bites and sun burns might fade, the memories and and physics lessons learned certainly will not.
Signing off for my last blog post-
Annie
Go Blues. Go Camping. Go Physics.
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